Roy Beck came into the population growth and immigration reform movement with superb credentials as an award-winning journalist. This article in which he brings the research of Leon Bouvier into clear perspective was the beginning of a thrust into lobbying and writing that led to several books and the creation of NumbersUSA of which he is executive director.

A new computer study requested by The Social Contract shows that immigration is a far greater contributor to U.S. population growth than usually stated. In fact, during the last twenty years immigrants and their descendants have contributed more than half the growth.

The news media almost universally say that immigration contributes to about a third of U.S. population growth each year. Even people concerned about high immigration have been heard to use the figure. One-third is a very important proportion that demands attention. And it is substantially accurate, but only in terms of a single-year perspective.

The one-third figure seriously understates the full population impact of immigrants and their fertility rates over a longer period of time, according to the work of demographer Leon Bouvier. He is former vice president of the Population Reference Bureau and adjunct professor of demography at Tulane University School of Public Health.

His results open the way for the use of these much more powerful statements of the impact of immigration

* Immigration is not simply a major force behind growth; rather, immigrants and their descendants have been the No. 1 ingredient in U.S. population growth since 1970.

* More than 50 percent of population growth since 1970 has been caused by immigrants and their descendants.

* New immigrants and the descendants of other post-1970 immigrants are likely to contribute two-thirds of population growth in the ‘90s.

* The institutionalization of environmentalism began around 1970, and a presidential commis-sion recommended population stability, yet federal immigration policies have resulted in an additional 24 million Americans, with no end in sight.

* Baby boomers surprised demographers by having small families and thus reducing the expected population growth. But immigration doubled that growth.

Why then do almost all public pronouncements limit the impact of immigration to one-third or even less?

It happens because it is one accurate way to state proportions and is the easiest, Bouvier says. If you consider the start of each year a blank slate, you simply add up the number of known net immigration during that year say, 500,000 and relate that to total population growth say, 1.5 million. Thus, you have a one-third proportion.

But that method never considers the fact that in ensuing years immigrants have babies and their babies grow up and have babies, all at significantly higher rates than for other Americans hence the caveat "and their descendants." An example of how misleading the simple method can be is found in "The World Almanac and Book of Facts 1991." It shows that "natural increase" of Americans was responsible for 71 percent of growth during the '80s while new immigrants made up 29 percent of that growth. But by the end of the decade, a larger and larger portion of that "natural increase" was the descendants of early-'80s immigrants.

Bouvier's method provides a much cleaner picture and also accounts for illegal immigration without having to rely on estimates. He did this by asking the question What would have happened to the U.S. population had there been no immigration? He built on reliable U.S. Census data. He took the multi-ethnic 1970 U.S. population of 203 million and the way it was known to have broken down by age and gender. He applied fertility and death rates of the period and ran the age groups through the computer program.

Once he found how many people today were here in 1970 or are descendants of that population, he knew the rest of the population had to have arrived as immigrants since then, or be their descendants.

The year 1970 was chosen as the benchmark because it began the decade in which the modern environmental ethic was formalized in many govern-ment policies. It also was the time of the first Earth Day and part of a period of much public clamor for halting population growth for the sake of the environment. In 1972, a presidential commission concluded there were no substantial benefits from adding any new population and that resolution of many environmental, social and economic problems would be enhanced by population stability. Bouvier's figures point dramatically to the ignored warning.

Even without immigration, of course, the ‘70-vintage Americans were bound to grow on their own because the gigantic generation of baby boomers was moving into child-bearing years. Growth was not as high as it might have been because boomer women averaged less than two children each. Nonetheless, they were responsible for an extra 11 million Americans by 1980, Bouvier found.

But their environmentally and socially respon-sible behavior on family size was substantially negated by the nation's immigration policy which more than doubled the population growth to 23 million by 1980.

Without net immigration, Americans would not have added 23 million to their number until nearly 10 years later.

Imagine life today with only 1980's population - only the same number of automobile drivers as then and without the urban sprawl that has been added during the last decade!

In fact, the nation added 48 million people from 1970 to 1990. Of these, almost 25 million were the result of U.S. immigration policies.

Post-1970 immigration forced the nation to contend with the pollution, infrastructure require-ments, and space needs equivalent to adding to the country another New York City, Chicago, Los Angeles, Philadelphia, Detroit, Memphis, Washington D.C., New Orleans, Cleveland, Miami, Newark, Buffalo, St. Louis and, to round it out, 15 more cities the size of Las Vegas.

But Bouvier's projections paint an even more heart-rending portrait of what might have been.

Without net immigration, the baby boom echo would have been starting to grow faint by now. The 1990s would have been a time when the population growth curve began to flatten. The '70-vintage Americans, under the projections, would have had 65 years to adjust local and national frameworks to the additional Americans that in fact have been added in only the last 20 years.

Bouvier shows that the baby boom echo, and echoes of the echo, would have run out of steam allowing the population to top out at 247.2 million in 2035. Instead, under current immigration policies and fertility rates, we may be looking at 350 million people and still growing by 2035 another 100 million people. That's more than twice the increase that has created the incredible congesting of America during the last two decades.

And during the '90s? Bouvier's compilation shows that '70-vintage Americans would have created a nation that would grow only by 8 million during the '90s. Instead, U.S. Census projections indicate, we're probably looking at between 24 and 26 million more people!